Braking device for cinematographic spools



J y 93 EJSAINTE-CLAIRE-DEVILLE 1,863,078

BRAKING DEVICE FOR CINEMATOGRAPHIC SPOOLS Filed April 19. 1929 2 Sheets-Sheet vl Fig.4

y 1932- E. SAINTE-CLAIRE-DEVILLE 1,368,073

BRAKING DEVICE FOR CINEMATOGRAPHIC SPQOLS Filed April 19, 1929 2 Sheets-Sheet 2 (I Ma I I I a:

Patented July 19, 1932 UNITED. sTAT s PATENT form r f" ETIENNE SAINTE-CLAIRE-DEVILLE, or PARIS, FRANCE, ASSIGNOR. ro soornrn mas T LIssEME-Nrs 'GAUMONT, or rams, FRANCE, A QQRPORATIO OFTFRANQE h BRAKiNG DEVICE FOR. CINEMATOGRAPI-IIQSPOOLS Application filed April 19; 1929, Serial No. 356,584, and finance Ma 12, 1928."

In the apparatus for cinematographic projection s, the film is usually disposedlat the upper part upon a slightly brakeds'pindle and the supply'or feed is secured by means of a toothed cylinder which pulls the film by means of perforations. At the beginning, when the spool has a large diameter, the tensile strain on the film is comparatively small but the same increases according as the diameter of thespool decreases and is comparatively large when thespool is almost entirely unwound; Inversely, at the moment the rewinding operation takes place at the lower part of the apparatus, the tensile strain on the film isvery strong at the' beginning andthen gradually decreases so as to be what it ought to be; that is tosay is just as required at the end of the rewinding operation; The result is that the wear of the perforations issomewhat alarge one and that the film can pass but in a relatively small number of times through the projecting apparatus, the film having thereafter to be thrown "away.

The braking device used inconnection with 1 'cinematographic spools and formingthe object of the present invention has for its purpose to avoid this inconvenience andto allow a relatively constant tensile strain on the film when the same enters the apparatus, this "strain being adjust-able according to the re-' quirements. V a

The said device essentially consists a plate driven by the spool its revolving motion the said plate' being subjected to a triotion of constantiintensi-ty by means of a clasp with adjustable tightening action which enters into .agroove provided in the plate and whose shape is that. of an Archimedean spiral I so that whilst the film Windsor unwinds itself, the torque acting upon thespool remains proportional to the instantaneous diameter of the spool; that isvto say thetensile, strain on the lfilm willremain constant. I V j -The invention has also for its purpose a subduing device combined with the above defscribed braking device'and allowing to rencler its operation entirely automatic and to secure particularly on the one hand, at the F a beginning of the unwinding operation 'of the spoohthe correct positioning ofthe the spiral provided thereon as clamping or tightening clasp.

clamping or tightening clasp and, on the other hand, at the end of the unwinding operation, the return of the said claspto its start-' ing position. 1 i To this purpose,'the articulated lever carrying the clamping or tightening clasp or claw is subjected to the action of a compressing spring which is tightened when the cover of the storing case forthe spoolis' being closed after the said spool has been placed-in position and which upon opening said cover will untighten so as to sendflback the lever into its original position.

However, for preventingthej fin er or pointer carriedby the clasp, which iollows the spiral groove on the plate, to eXer-t,--under the influence of thecompressed spring, a detrimental reaction upon the wallsof said groove, a special automatic locking 1 device has been provided for limiting the compression ofthe spring to a constant valueand.

for placing-the same during the; operation in a condition of static balance in'which it will not exert any action upon the lever ;"the said action being exclusively started: at the end of the unwinding operation for'the pur-' pose of returning the lever to its original position, i The following description made with reference to the accompanying drawings, given by Way of example, will allow easy understanding of the i i is carried out.# i, l

Figure 1 shows in adiagram the plate with well as the Figure 2 is a section made through the axis ofthe core of a spool to which is adjoined a'braki'ng plate in case the spool is dr1ven=bythe rotary motion exerted upon thefi'lm. 1

wayin which the invention Figures 3 and 4 are views's imilar to Figs. '1'

and 2 respectively illustrating the casewhere transmitted toits axis. F I l H Upon the storing case or magazine adapted to contain the film spool and generally the rotary motion of the spool "is directly mechanism which is shown in Figures- 5, 5, 6.;73 d i3 "known as fire protecting 'case;fis mounted the j of gears.

Figure 5 shows a case or magazine infront view the cover being open.

Figure 6 shows diarammatically in a broken section, the profile of a part of the 5 mechanisln'of the Figure 5.

Figs. 5 and 7 .shw diagrammatically in section on line a'5a of Fig. 5' and in plan view parts of the mechanism of Fig. 5.

Fig. 8 is. a section on the line 88 of Fig. 7.

In Figures 1 and 2, the upper spool-hold- 1 ratio connects the spool-hold'ingspindle '3 and the plate 4. The said plateis. provided .wi tha groove in the form ofa spiralo in -Which the distance between two consecutive windings or coils, calculated according to 2 a radius,'is equal to the mean thickness of the film multiplied by the ratio of the set the direction of the radii increasing upon the 'sa id spiral is the same as the one in which the film, is wound. A clasp 6, with elastic adjustable tightening action articulated at 7 follows throughthe medium of a pin 8 the I q roove the clam in or ti htenin action k?! D Z) 3 of the clasp -6 being adjusted by means of a screw -60 according to the tension which. it

A is desired'to. give to the "film. The operation is as follows: p 7 .lllhe, pin of the clasp or claw 6 is placed at V therwme di-stancefrom the axis ,or spindle as-the'periphery of the spooL. During the unwinding of th-e'ispoolaif the ratio of the .Sfitidf gears has iudiciously selected, the pin 'ialways remains at the same distance from theaxis asthe periphery ofthe spocl,i

and ,thseamwinding of the film requires a I tractive effort which is. always substantial-- 1 1y equal to the frictional resistance exerted by the clasp, the constant and comparative ,15 little important frictionsof the set of gears being neglected. QIn the case shown in Figures 3 and 4, the

to therewinding of the film.

' The frictional system 9 which'is'usually employed for securing the rewinding operation is maintained, but is adjusted in such manner that it will beable to-drive in its revolving motion both the spool 2 carried'by the spindle and the grooved plate 4 on'which,

is provided the clasp with elastic adjustable I {tightening or clampingaction. In. this case,

at the r -start'of the 'rewinding operation, the point ,atwhich the clasp will be applied will be at a distance from thev center equal to the -radius of theispool whensaidspool is completely wound,' and'willbe'closer to the centerwhen the winding operation hasycome to j end; a In the absence of a braking action,

' h thestrain transmitted to the film through Therefore the said spiralis sub-- .stantially an Archimedean spiral. Moreover,

friction, would be at the beginning of the .winding operation greater than at the end of the latter, for thesame reasons as those whichhave'been hereinbefore mentioned; if at the beginning of the winding operation, the clasp 6 is placed at the same distance from the axis or spindle asthe periphery of the spool which is supposed to be wound, the

driving motion of the core will be brakedl and accordingly the pulling or'tensile strain of the core upon the film wi-ll be reduced. The said braking strain is regularly decreasing from the beginning to the end of the winding operation and it will be easy to adjust the value or power of friction 'ofthe clasp so that thefresulting pulling strain exerted upon the film will be practically a constant one.

If the use of these devices is particularly desirable in connection with projecting ap- .paratus, the same canju-st as-wegllhe applied to printing and. developing apparatus, and

the like. 7 i

' In the projecting apparatus in which the film is continuously in motiomit presents a Y still greater advantage, such an arrangement assistingtogether with the princip'leof continuous unwinding in avoiding every cause I of damage to the perforations of; the film, whatever maybe the through theapparatus. r Y

The subduing' device combined with the above described braking device and allowing 7 number of passes to, render its operation entirelyzautomatic may be executed as follows: 1

' Within a cylinder 10 secured to the body of the magazine or storing case 11 (Figures .5 and 6) is slidably mounted-apiston 12 connected through a rod 13 and a small link 14; I with the lever 6. This lev l 6 which is'articulated to a pivot 7 secured to the body ofthe storing case carries at one end a blade 8* acting as a spring and to which is riveted a finger 8. Thelever Gisfork-shaped ashere 7 .inabove described and clamps betweenits 1 arms or branches a plate 15 driven together with the spool and provided with Archi- 8 is engaged.- The stroke f he l r stop 16 and towards theleft by the spiral V medean spiral groove' 15* in which the finger g principle of the first. device has been applled V -towards the right is limited by an adjustable groove, of the. plate "15. The piston 12 is 1' spring-loaded in apermanent mannerbya Y compression spring 17 which bears,- onthe one hand, upon the left face of'thep'iston,

tending to push the latter towards the right and on'the otherhand, upon an abutmentv collar 18 ada pted to be bound with the lever 6 at the moment the cover 53 of the storingcase 11 is being closed means .of aspecial of anextraneous inafter indicated, A lever l9 ofa special form with a double pallet is pivoted to an' axis 2O rigidly secured to the storing case in a manner that has not been shown in the drawings in order not to intentional power, as here unnecessarily complicatethem, said lever 19 being normally parallel with the bottom of said casing. The said lever 19 tends to rock 'in the direction of the arrows 22, under the influence of a compression spring 21; The

lever 19 carries, upon its lower pallet,'a sleeve 23 which slides upon the spool-carrying spindle24. Moreover, said pallet isprovided with a hole 25. Saidlever 19 comprises an upper pallet 26 which is not rigidly secured thereto, but yieldingly due to atension spring 27 the action of which is howeverlimited by a'stop 28 secured to the lever 19. Said upper pallet 26 carries in a slot 26 which is pera I pendicular to the plan of'Figure 6, a finger when the finger 29 engages the'recess 12 of:

the rod of piston 12, onthe one hand, the stop 18 is bound with the piston 12 by means of the finger 29 and that, on the other hand the lever 6 is bound with said stop through the medium of the rod 13, the piston 12'and the'finger 29. The spring 17 is thus maintained in a condition of static balance between the piston 12 and the stop 18 which are stationary relatively to one anotherand said spring has no action whateverupon the lever 6; this action of spring 7 on the lever-6 can only take placewhen at a determined moment, the finger 29 is disengaged from the recess 12" thereby releasing the piston from thest0p 18.

In this manner, during the unwinding of the spool the finger 8 of the lever 6 is preventedfrom exerting a detrimentalreactionupon the edgesof the groove provided in the plate which would be the case if said finger were constantly pushed toward'theright by spring 17, whilst said spring 17'is kept compressed and is 'capable of acting at a given moment upon the lever 6.

' Another single-pallet lever 30 is pivoted upon an, axis 31 inparallelfrelation with the axis 20. This lever 30 isinfluenced by a twisting spring 32 whichacts in the direction' of the arrow 33. To said lever 30 is secured a finger 34 having a shoulder and engaged in the ',hole of the lever 19'. Thespring 32 isjust suflicient to securethe contact of said shouldriving the lever in 38secured to the stationary part cannot cause said-lever19 to rock.

derjwith'tlie lower pallet of the leverbut Th shoulder onsaid finger34 is used for 7 v p ihe rocking motionof the lever l9-along the arrows 22. a

1 The lever '30," through theright end of its pallet (Figures) bears upon the spring blade 8 forming an extension ofthe lever B, in such a manner that in the rocking motion of the lever 19 along-thearrows 22, thefinger=8v is plate 15.

the spindle 24 whose knuckle arm 36 is told "ed'downther'eby maintaining the spring 21 through'the mein a compressed conditio upon a n-axjis or bottomof case'll is influenced by, aspring A'lever 37 (Figure7) pivoted the storing 39 in the direction of the arrow 40. A'tthe disengaged from the spiral groove in the The spool igure 6) is mounted end of the-lever 37 is coupled through the niediumzofthe small link 41 a hooked slide 42 which keeps inengagement with a rocking lever 43 pivoted -at144.-" This lever can-rook under the influence of'aflcompression spring 45as far as a stop 46, and is pivotally mount ed on asecondslide'47l i Said slide-47 isconnected through rods 48 and arms48 with the stop '118fJ-'(Figurei 49 (Figure 8) secured to the .bottomof the magazine 11.x At a certainmomentof the dis- ;95 :Both slides 42 a-nd 47 are guided in a-frame I placementof slides 42 and 47 toward the right,

whencover 53 is beingclosed, the-end 5010f the rocking lever 43 comes incontact with a slope 51 provided "on the lever 6, (Figures 5 and'?) and rises along the latter-thus disen- I I gaging slide 47 from slide 42.

cover.53 ofthe magaz1ne,said coverbeing pivoted upon the hinge 54. the end of provided'a finger 55 w'l1ich, in V of the lever, meets and drives the lever 37. Theope'ning'of thestoringcase has forzits efi'ectto-driveth'e levers 37and 52' the lever 52 is the. movement along the arrows 40and '56. v

Such aflsubduing' device-:being upon each of the storing, casesdna cinematographic apparatus, theoperation willlbeas follows? 2, a i

The ope-rator places the adjiustablestop l according to, the length of the spool film heis 7 going to mount on the uppen-spindle and folds down the knuckle-part36, this result- 21 and iii-stretching the spring 27 which will act upon-the lever in the reverse directions of 1 12a ing in forcing the sleeve 23, against the spring s :the arrows 22 as soon as the finger 29 ,lies opposite the recess providedin the piston 12. i. The leVerESO is urged in'the direction of the engages the spiral groove on will I site will be exactly: opposite theisamegga 1 12-1' -arrow, 33 and the finger 8 'carriedby theflexij -ble blade 8 :engage as soon a +'-U .ponosurie'of, the ceve 3, he-lev r 5. drives the ever hrough the med um of h finger 55-ther byrdete mining a shifting mpiston rod thus compressing v the, finger29 which can 'extent'to allow the hookflto until the lever raising. a

' unti th case i or V opp site the recess enters the latter thereby connecting the leverv '6 tothe stopcollar18, as-aboveindicated.

The stop. 18 is thenrconnected to the piston 12 through the medium of finger 29, andwill accompany the same towards the left, during all the I 'fShou-ld ithappen that,-..or any reason, the operator would open the storing case,- during the. operation,

cause the lever 43 to, rock justtoa sufiicient "closure of-the storing. case,the hook of the slide .42 will drive the slide 'ftfor a very fs'hortmoment until-the end of the lever 4l3 the'knuckle-part 36; 7 The spring21" is free i theleverfi (Figurefi) ossibleby the 'fact'that' owing to therotation f ger 8 has 'loeen simultaneously disengaged from the spiral groove by I Q the "lever- 30, which is rotated toward the] v fsame positions asloaded;

has'ascended the slope 51, thereby disengagfl ing the levenlii from-the hook of the slide 42 and theopening of the. case will in no respect affect the difierent parts of the mechanism. For the purpose of starting the winding of the; film uponthe rewindingspindle, the same operations beperformed in .t-he

7 Q; same sequence.

Whenthe projectionis finished, the operator withdraws the spool. after swingingup to push on "lever 19, whichvr'ot'ates in the direction of arrows '22, whereby the finger 29 will be" disengaged from the recess 12 of the piston rod,liberating' said piston which, will'force.

iunder'j he action of the spring17,

the stop 16; during that stroke,- the piston compressesf'the air contained in the space of the cylinder 1 situatedlbehin d thepiston 1'2 for the purpose-of-absorbin-g the. shock consequent-to the lever 6 'cominginto contact w ee-0916 V a Back imoveme'nt of the lever 6 is made of *lever 19 the fi igh hm fi sfi r3 r I I 1 The various'parts therefore assume: the when th'eapparatus was I The'stop 16 is adjustable so as' 'to conscientious operator to'work with anever 'gagesaid; plate, and v op ra e *with he' spir l g oo f r g id ng I time the apparatus is in: operat on. I

according 'to the position of thel'ever '6 at this moment, the slide 42' can pass, then upon follow "the groove,

''ing the plate-to'rotate the spool at a suitabler'atioofrate,,a clasp tothe right as'far as V adaptedltoi-ricpl spdapt l w th o em- Y me s f ary ng e. clampin action a o the-clasp upon'the plate.

cinematographic apparatus,

te frioti'onallyi engage said plate,

actionofthe'clasp upon th'e'p'late and means V the clasp-to its original posi was slightly stronger in the; unwinding and a littlemore slack upon rewinding when dealw nd 1 0p i a n si ien eqr d s ore ould rema n d sadvan g sulting" ring with spools having small lengths.

- =What 1 claimis:

1. In a braking to r a e s ltene ously with the spool, a clasp pivoted on" a fixed point and adapted to,

m ans e ice 01: t sr o Qt i s ep p j n apparatus, a plate provided with a, spiral groove,means iforcausingv the, plate fri ienally e r" dapted t 9,-"

the freeend of the clasp upon the plate. 1

In a 'device ior braking the spools "or cinema g ph lil l C Ql apr et a plate provlded wit spiral groove, means for causing the plateto rotatesin ultaneously point and 2 with the spool, a clasp P O Q Q lvaa ifi A a p e r ionally engagea-i 11P tefi s upon d'e na aP Qd to follow and means for varying the clamping action O f-the claspuponthe plate. W

the groove providedintheplate r 1 I 3. In ,a'devi'ce' for braking-the spools, of A cinematographic projection apparatus, a

plate provided witha spiral groove,-a set of gears interposed between the saidfplate point, and adapted to frict-ionally enga said plate,

plate. I

1 4. In a ieinematographic apparatus, a plate ro- -p v ted one fix d po n n ti n y l ng e Said p e, afi ger on sa d 1w and the spool; a clasp pivoted on' fixed 7 a finger on said clasp adapted to V and means for varying V-th'e clamping actiorrofthe clasp: upon the its" device for braking the spools/of 5. In a devicefor Qb'jr'aking the spools t I a plate provided with a spiral groove, means forlca'using said a clasp pivoted ona fixedpointarid adapted said clasp adapted 'to' follow the means for varying the clamping for returning 7 tion at the'jend of the revolution 'offthe 'spool.

-6. Ina device for braking the spools of cinematographic projection apparatus, a 7

groove of i film magazine, a coverrotatably mounted on said magazine, a spindle adapted to receive a spool of film, a plate adapted-to be driven by said spindle and provided with a spiral 5 groove, a clasp pivotally mounted on the magazine and adapted to frictionally engage said plate, a linger on said clasp adapted to engage the spiral groove of the plate, and means combined with the cover of the maga- 1 zine for returning the clasp to its starting position when the cover of said magazine is open at the end of the revolution of the spool, and the spool is removed from the spindle. V 1 7. In a device for braking the spools of cinematographic projection apparatus, a film magazine, a cover rotatably mounted on said magazine, a spindle adapted to receive a spool of film, a plate adapted to be driven go by said spindle and provided with a spiral groove, a clasp pivotally mounted on the magazine and adapted to frictionally engage said plate, a finger on said clasp adapted to engage the spiral groove of the plate, a g; cylinder mounted on the magazine, a piston in said cylinder, a slidable stop in said cylinder, a spring interposed between the piston and the slidable stop, a rod for connecting the piston to the clasp, a system of articu- 10 lated levers connected to the cover for mov-- ing said stop so as to compress said spring at the beginning of the operation, when the cover is closed, means adapted to lock the stop on the piston in this position, and a 35 system of pivoted levers for releasing said lockin means when the cover is open at the end 0? the operation and the spool is removed from the spindle whereby the piston is pushed by the spring, thus returning the o clasp to its starting position.

In testimony whereof I have signed this specification. l

ETIENNE SAlNTE-CLAIRE-DEVILLE. 

